1. Field of the Invention
This invention relates to the attachment, at a precise position, of a first member to a second member which is not as precisely positioned as the first member, and provides a method of and apparatus for locating the position of the first member and for reforming the second member by a variable magnitude depending on the actual position of the second member relative to a predetermined position. The invention relates, in particular, to the precise attachment of an outer body panel member of an automotive vehicle to an imprecisely located element of an inner body panel structure.
2. Description of the Prior Art
U.S. Pat. No. 4,438,971 (W. S. Zaydel, et al) describes a method of and apparatus for attaching, at a precise location, a plastic automotive body panel to a relatively imprecisely located element of an inner body panel structure. According to the teachings of this patent, plastic-filled metal attachment blocks or pads are welded at selected locations to the inner body panel structure. The inner body panel structure is then positioned within a locating and machining fixture and each of the plastic-filled attachment blocks is milled to a precise position, the distance between the inner body panel structure and the milled face of the plastic-filled attachment blocks varying with the position of the inner body panel structure. The plastic outer body panel member is then attached to the milled face of the plastic-filled attachment block, after drilling a hole in the plastic-filled attachment block to receive a threaded fastener or a fastener attached to the inside of the plastic outer body panel member. By this method and apparatus, each such plastic outer body panel member is mounted in a precisely determined and in precise surface alignment with each adjacent plastic panel.
The method and apparatus of the aforesaid U.S. Pat. No. 4,438,971 does lead to precision in the positioning of plastic outer body panels to a relatively imprecisely positioned automotive inner body panel structure, but it requires the initial attachment of the plastic-filled attachment blocks to the inner body panel structure, a factor which adds to the material and processing costs of producing an automotive body in this manner, and the welding operation that is needed to attach the plastic-filled metal attachment blocks is noisy and dirty. Additionally, the subsequent milling of the plastic-filled attachment blocks generates scrap which is a mixture of a metal and the plastic filler material which, for the disposition of such scrap in an environmentally acceptable manner, involves additional expense and, in any case, the milling of the plastic-filled attachment blocks generates dust corresponding, mainly, to the composition of the plastic filler. This is also objectionable on environmental and workplace health and safety grounds, unless strict precautions are followed in performing the milling and drilling of the plastic-filled attachment blocks.
It is also known in the prior art that a relatively imprecisely located automotive inner body panel element can be built up to provide for the attachment thereto of an outer body panel element at a more precisely determined location by attaching one or more metal shims to the surface of the inner body panel element to which the outer body element is to be attached, the number of such shims to be attached based on the original position of the inner body panel element. However, this is a time-consuming and expensive procedure, and the attachment of such shims adds to the weight of the vehicle, an undesirable feature especially since it detracts from fuel economy.